Add guide for working with TS, MUI, next.js

[humphd]

We're using TypeScript with next.js, React, and Material UI, and there are lots of quirks and things to know.

I've been using these docs and examples a lot:

• https://github.com/typescript-cheatsheets/react#reacttypescript-cheatsheets
• https://material-ui.com/guides/typescript/
• https://github.com/vercel/next.js/tree/canary/examples/with-typescript
• https://github.com/vercel/next.js/tree/canary/examples/with-typescript-types
• https://github.com/vercel/next.js/tree/canary/examples/blog-starter-typescript
• etc (see https://github.com/vercel/next.js/tree/canary/examples for more examples)

We should consider adding some doc with links that we can use to point contributors at.

[chrispinkney]

Good comment from Abdul here:

We should probably update docs at some point or make some sore of note that we don't use FC. I know it's widely known at this point but I'm sure people new to TS might have some questions about that